Commutator for d yn am o-electri g machines



(No Model) T. E. ADAMS.

COMMUTATOR FOR DYNAMO ELECTRIC MACHINES.

No. 340,537. Patented Apr. 27, 1886.

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UNITED STATES PATENT OrEIcE.

'lllOllAS E. ADAMS, OF CLEVELXND, OHH).

COMMUTATOR FOR DYNAMO-ELECTRIO MACHlNES.

SPECIFICATION forming part of Letters Patent No. 340,537, dated April 27, 1886.

Serial No. 184,524. (X0 model.)

To a'ZZ whom it may concern:

Be it known that I, THonms EDGAR ADAMS, of Cleveland, Ouyahoga county, Ohio, have invented certain Improvements in Commutators of Dynamo-Electric illiachines, of which the following is a specification.

My invention relates more particularly to that kind of commutator of which the Brush commutator is a type, in which the segments are so arranged that the several bobbins of the armature to which they are connected are cut out of electrical connection with the remainder of the circuit during a portion of each revolution.

The object of my invention is to provide a cutting-out segment or insnlatingpiece be tween the metal segments of a commutator which will have a higher resistance to the passage of the current from one metal segment to the others than those now in use, and also by reason of its antifricti0n qualities to reduce the tendency to cutting between the contact-brushes and the commutator.

In the accompanying drawings, Figure 1 is a plan view of a commutator having my improved cut-out segments. Fig. 2 is an end view of the same. Fig. 3 shows a detached segment in perspective. Figs. and 5 show in side and top views a modified form of the invention.

For illustration, the Brush commutator is.

chosen as a form well known; but I do not limit myself to any particular form of commutatoix A A represent my improved segments. They are preferably made of lignum-vitm, though knots of deciduous trees and some other kinds of very hard and gummy woods are suitable.

The segments may he made of any suitable size or shape; but they should be provided with one or more Vshapcd grooves, a a, cut diagonally across their wearing-surface, to prevent the production of a continuous plated surface from particles of metal lodging on the segment. The grooves are cut diagonally, to prevent pounding of the contact-brushes as they pass over them. They are V-shaped in cross-section, to enable the centrifugal force to throw out any particles that may lodge in them. For durability and uniformity of wear.

wood and copper segments alternate. The

V-groovcs possess the further advantage of interposing so many airspaces for the spark to bridge. By making the grooves of the proper size and number the wear of these segments may be made uniform with the rest of the commutator.

To prevent charring on the end of the wood en segments, I provide refractory tips a, which may be of metal or of some vitreous material. Should the anti-friction qualities of this detachable cut-out segment be dispensed with, it may be made of any insulating material, and upon its wearing-surface have attached narrow pieces of metal, rawhide, or other substance capable of resisting wear, and having interstices or grooves between them. to prevent particles of metal from making a continuous path and allowing the current to pass. This form is illustrated in Figs. 4: and 5, in which A is the insulatingbloclc, and a c the wearing-strips.

These'detachable segments may be easily .a commutator, the insulating cut-out segment provided with transverse grooves in its wearing-surface.

4. In combination with the metal plate of a commutator, the insulating cut-out segments provided with transverse grooves cut diagonally to the axis of the commutator.

5. The combination, with the metal plates 5 of a commutator, of the removable cut-out segments provided with V-shaped grooves.

6. The combination,with the metal plates of a commutator, of the cut-out segments of insulating material tipped with refractory mate- I 10 rial at the end.

7. The combination, with the metal plates of a commutator, of insulating cut-out segments formed of wood and having the end grain presented for wear.

In testimony whereof I hereunto set my hand 15 this 1st day of December, 1885.

THOMAS E. ADAMS. Witnesses:

J. POTTER, ALBERT E. LYNCH. 

